Flame-proof insulating composition.



UNITED STATES PATENT OFFICE.

CARL-ETON ELLIS, 0F MONTCLAIR, NEW JERSEY.

FLAME-PROOF INSULATING COMPOSITION.

No Drawing.

To all whom it may concern:

Be it known that I, CARLnTo'N Thus, a citizen of the United States, and a resident of Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Flame- Proof Insulating Composition of which the following is a specification.

This invention relates to what may be termed flame proof insulation and relates particularly to a composition comprising chlorinated material of the nature of the chlorin derivatives of coal tar and the like.

The composition may be used with a conductor consisting of a copper wire having an insulating layer of rubber or other suitable material and a braided coating of cotton fabric or other tissue surrounding and protecting the insulating layer. ric is ordinarily saturated with wax or asphalt, or bodies of a similar nature which when ignited burn with considerable readiness causing the flame to spread along the wire and oftentimes do considerable damage.

If coal tar is chlorinated only to a slight degree it forms a product which does not permit the flame to travel along the wire after ignition has been started as by strongly heating at some point. Ordinarily coal tar preferably free from volatile solvents such as benzol and the like which have an undesirable softening action on rubber insulation and preferably also free from carbolic products of the nature of phenol as well as naphthalene and the like is employed. Coal tar, freed from phenol, naphthalene, etc., whether or not the benzol, etc., are removed, is referred to as liquid constituents of coal tar and similar expressions. Coal tar has the advantage of being a very cheap material and inasmuch as only a slight degree of chlorination is required the product can be prepared at low cost. Even the addition of about ten per cent. of chlorin forms a body of suitable flame proof qualities. Furthermore, the chlorination treatment tends to thicken the coal tar and give it the consistency required for the purpose. An example of the method of preparation of one form of the product is the following:

128 arts of commercial coal tar freed from light products was treated in the cold with chlorin in the presence of one-tenth of a part of iodin acting as the chlorin carrier.

Specification of Letters Patent.

The fab-.

Patented Dec. 4, 1917.

Application filed. August 5, 1915. Serial No. 43,743.

The coal tar was agitated while the chlorin was being passed through it and the mass heated to a temperature of about 5060 (3., when the vessel was exposed to the air with out any insulating material. The chlorination was allowed to progress slowly for a period of about five hours, at the end of which time the tar was found to be quite thick. The minimum gain in weight was approximately ten per cent. The product was washed with very dilute alkali to remove free acid and then was washed several times in water. This material was then heated until of the requisite consistency and a rubber coated wire having a cotton jacket was passed through this liquid. The tarry material was taken up readily by the fabric and the resultin composition was substantially flame proo In fact after holding this coated wire in a flame until the rubber insulation was burning briskly upon removal from the source of heat the flame died down. A form of the present invention involves the use of chlorinated volatile solvents such as chlorinated solvent naphtha. When this material is chlorinated at about 80 C. employing a small amount of iodin as a carrier so as to take up 45-50% of chlorin a large quantity of solid crystalline material is obtained which may be separated from the mother liquor and freed from'acid by washing with alkali. White crystalline needles are obtained which may be placed in a suitable solvent such as benzol or any other medium which may be used under the circumstances and the fabric used in insulating wire treated with this solution. The fabric may be obtained interlaced with crystals in the spaces between the fibers. The wire may be then passed through a bath of wax or porated with other suitable material such as asphalitic bodies and the like or chlori observed that rubber is not necessarily employed but the entire insulation maybe made of flame proof material or other suitable insulating material admixed with or coated with flame proofing compounds.

When rubber is used the product employed for flame proofing should be compatible with the rubber so as not to soften, dissolve or rot the rubber compound.

Inorganic fire proofing agents such as the tungstates and phosphates of ammonia and the like may be used in conjunction with the chlorinated material if desired, especially in cases Where a strictly waterproof insulation is not required. To recapitulate, my invention relates to an insulating composition comprising a chlorinated hydrocarbon and more particularly a mixture of chlorinated hydrocarbons, preferably liquid hydrocarbons, of an aromatic nature, such as solvent naphtha and similar hydrocarbon mixtures; including crude forms thereof embracing coal tar itself but preferably a chlorinated hydrocarbon of a crystalline nature, such as may be obtained by chlorinating coal tar hydrocarbons, particularly solvent naphtha, yielding a chlorin derivative or a complex mixture of chlorinated derivatives with which may be incorporated other suitable bodies such as as phalts, waxes and the like including various forms of combustible organic plastic insu-' lating material, such materials being suitable for use inconnection with the coating of wires to form a flame proof product, as preferably a suflicient quantity of the chlorinated material is used to suppress or greatly retard the combustibility of the other constituents so that when wire with this type of insulation is ignited and'inflamed at one point, the flame does not travel along the wire readily and the fire is localized.

The fiameproof composition with which the cotton insulation is impregnated, in accordance with the preferred form of the invention, is very plastic and non-brittle, so that even fine copper wires, with the usual coating of inflammable insulating material and a winding or braiding of cotton or other textile material, can be treated with the flameproof material, without detractin niaterially from the flexibility of the'insu ated wire. The fiameproof material is distinchydrocarbons of solvent naphtha, said composition being flame proof but containing combustible components.

2. An insulating composition comprising chlorinated solvent naphtha of a crystalline character.

3. An insulating composition comprising chlorinated. solvent naphtha and other insulating material.

4. An insulating composition comprising chlorinated solvent naphtha and asphaltic material.

5. An insulating composition comprising asphaltic material and sufiicient chlorinated solvent naphtha to render the composition substantially flame proof.

6. An insulating composition comprising a combustible organic plastic insulating material incorporatedwith a chlorinated normally liquid coal tar compound of a noninflammable character; sufficient of the latter being present to render the composition substantially flame proof.'

7. An insulating composition comprising combustible plastic insulating material incorporated with the chlorin derivatives of those portions of coal tar left after removing the readily volatile constituents, phenols and naphthalene, the said chlorin derivatives being present in amount sufficient to render the composition substantially noncombustible.

8. An insulating composition comprisin combustiblev insulating material incorporate with the chlorinated derivatives of liquid components of. coal tar; the proportion of the latter being suflicient'to reduce the inflammability to an extent such that if ignited at any-given spot the flame does not travel along the surface of the composition for any substantial distance but is duly extinguished by the presence of the chlorinated constituent.

, 9. Aninsulatingcombustible plastic comprising insulating material incorporated with a complex mlxture of chlorinated volatile solvents of the solvent naphtha type; the proportion of the latter being sufficient to reduce the inflammability to an extent such that if ignited at any given spot the flame does not readily travel along the surface of the composition for any substantial distance but is duly extinguished by the presence of the chlorinated material.

10. An insulating composition comprising readily ignitible insulating substances incorporated with chlorinated normally liquid coal tar hydrocarbons containing at least ten per cent. of combined chlorin, said composition being substantially flame proof but containing combustible elements.

11. An insulating composition comprising chlorinated oily tar constituents and other insulating material blended therewith.

- 12. An insulating composition comprising chlorinated liquid hydrocarbons of tar containing at least ten per cent. of combined chlorin, said composition being substantially flame proof but containing combustible elements.

13. A flexible insulated wire coated with a combustible plastic insulating material and a textile material, said textile material being impregnated with a crystalline chlorinated organic solid of a non-inflammable character, a sufficient quantity of the latter being present therein to render the said composition substantially flameproof, so that flame will not travel along the surface of the composition for any substantial distance, but is extinguished by the chlorinated constituent. I

14. An insulating composition comprising a chlorinated normally liquid tar material of a non-inflammable character, sufficient of the latter being present to render the composition substantially flameproof.

15. An insulating composition for coating wire comprisin combustible insulating madoes not travel alon terial incorporated with chlorinated derivatives of liquid components of tar; the proportion of the latter being. sufficient to reduce the inflammability to an extent such that if ignited at any given spot, the flame the surface of the composition for any su stantial distance but is extinguished by the chlorinated constituent.

16. A flexible metallic wire having a coating of combustible insulating material and a textile coating, said textile coating being impregnated with chlorinated hydrocarbons of coal tar containing at least 10% of combined chlorin, the amount ofsuch chlorinated compound being suflicient to reduce the inflammability to such an extent that if ignited at any given spot, the flame does not travel along the surface of the wire for an substantial distance but is extinguished y the presence of the chlorinated constituent, said- 

